Filter for removing solids from gases



Oct. 13, 1936. RATHBUN 2,057,446

FILTER FOR REMOVING SOLIDS FROM GASES Filed Nov. 16, 1933 3 Sheets-Sheet 1 INVENTOR 1 ATTORN EYS Oct. 13, 1936.

R. B. RATHBUN FILTER FOR REMOVING SOLIDS FROM GASE Filed Nov. 16, 1933 3 Sheets-Sheet 2 INVENTOR ATTORNEYS 1936. R. B. RATHBUN FILTER FOR REMOVING SOLIDS FROM GASES Filed Nov. 16, 1933 5 Sheets-Sheet 3 y W: W M.

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ATTORNEYS Patented Oct. 1%., 1936 I FmrEn FOR REMOVING soLms FROM GASES Ross Buxton Rathbun, El Paso, Tex., assignor to American Smelting '& Refining Company, New York, N. Y., a corporation of New Jersey Application November 1c, 1933, Serial No. 698,300

7 Claims.

The invention relates to filters for removing solids from fluids in which the former are suspended. The invention is particularly useful in connection with the separation of fume from gas,

for instance in connection with such separation which is necessary in the smelting and refining of metals.

According to one form of practising the invention, the fume containing gas is passed into the interior of a substantially cylindrical porous bag' to deposit the fume on the inner surface of the bag. The bag may comprise a series of concentric fabric elements, as, for instance, a plurality of layers of steel wool. These layers are preferably stapled together at intervals, the staples being loosely bent to permit play between the layers. A wire netting may be stapled to the outside of the bag for additional strength.

A suction member may be provided within the bag for removing the deposited fume therefrom and thissuction member may 'take the form of a single nozzle extending the entire length of the bag and rotatable about the axis of the bag.

It is preferred to employ asingle opposed shoe 1 bearing upon the bag at'a part thereof which is diametrically opposite to the position of the nozzle. The nozzle is preferably exhausted into' a centrifugal dust collector in which the fume therefrom is deposited and from which the sub stantially fume-free gas is recycled to the interior of the filter bag.

Other means may be employed for removing the deposited'fume from the filter bag. For instance, a surrounding ring maybe employed for projecting a. fluid; against the outside of the bag and it is preferred to make this ring adjustable in the -'direction of the axis of the bag in order that jets of fluid projectedfr'om the ring may reach the entire outer bag surface.

Apparatus may also be employed for applying tension to the bagfrom its top and in addition there may be employed-apparatus for vibrating the bag by oscillating the same in the direction of its axis.

The invention also consists in certain new and original features of construction andcombinations of parts hereinafter-set forth and claimed.

Although the'novel features which are believed to be characteristic of this: invention will be par-.-

ticularly pointed out in the claims appended hereto, the invention itself, as toitsobjeots and advantages, and illen'lanner in which it may be carried out, may he better understood by referring to the following description'taken in con--; nection with the accompanying drawings forming a part thereof, in which Fig. l is an elevation of an apparatus constructed in accordance with the invention, parts thereof being broken away to show its interior? 50 Fig. 2 is a section on the line I I-Ilof Fig. 1;

Fig. 3 is an enlarged section through the lower part of the apparatus illustrated in Fig. 1;

Fig. 4 is a section on the line IV-IV of Fig. 3; Fig. 5'is an elevation of the apparatuses viewed from the right in Fig. 3 showing in greater. detail 5 some of the parts; I

Fig.6 is a vertical cross section of the upper part of the apparatus viewed in Fig. 1 on an enlarged scale; A

Fig. 7 is a fragmental section on the line VII- 10 VII of Fig. 6;

Fig. 8 is a fragmental elevation of the filter bag partially broken away to show its construction;

Fig. 9 is a cross section on the-line IX-IX of 15 Fig. 8; and

Fig. 10 is an enlarged fragmentail cross section of the bag section shown in Fig. 8, taken'on line XX.

In the following description and in the claims, 20 various details will be identified by specific names for convenience, but they are intended to be as generic in their application as the art will permit.

Like reference characters denote like parts in the several figures of the drawings. 25

In the drawings accompanying and forming part of this specification, certain specific disclosure of the invention is made for purposes of explanation, but it will be understood that the details may be modified'in various respects without 30 departure from the broad aspect of the invention.

Referring now more particularly to the drawings, it will be seen that they show a substantiah ly cylindrical filter bag' I2 and asingle nozzle l3 extending substantially the'entire length of the 35 bag [2. The fume-laden'gas enters the interior of the filterbag i-2 from the pipe 69, passes through the bag and enters the exterior chamber 12, whence it is exhausted from the apparatus.

chamber 12 substantially free of fume. Main suc-= tionblower Hi serves to draw thesgas-lad'en fume through the bag. I

The bagpreferably comprises aplurality. of 45.

layers i4, l5; l6 and ll of steel wool held together by staples It at intervals in both directions (see Fig.8); The staples are loosely. bent to permit play betweenthe layers audit will be seen-byre- -.ferring to Fig-'10 that although the staples held 50 the layers together effectively, they do not pinch them oneagainst the other so as to prevent a sliding motion of one layer with respect to its neighbor. Further, it is preferred to dispose the sepa rate layers of steel wool so that the strands in any .layer will lie at right angles to those in an adja= cent layer. Such an arrangement produces more effective filtering, greater ease in cleaning the bag and. greater strength in the bag itself. This constructionis best illustrated in Fig. 8. Howso or accidental contacts with its outside. Finally, a-

covering of wire mesh l9, stapled by staples I8 or otherwise fastened to the outside of the bag provides greater strength and rigidity and produces a more durable and. satisfactory filter bag.

The bag may be rigidly connected to the surinstance, by an annular angle section 20; and it is preferably supported by resilient means at its top. This means applies tension to the bag at its top but does not hold it rigidly. As here illustrated, (see Fig. 6) the resilient tension support comprises a plurality of levers 2 I, each having one end attached to a tie-rod 22 which in turn is fastened to the bag top and each lever 2| also having a counter weight 23 upon the end thereof which is distant from the end to which the tierod 22 is fastened. A pivot support 24 carries each lever 2| at a point intermediate its ends. The top of the bag includes a'ring Hill of angle section having metal plate IUI forming the end wall of the bag.

Means may be provided for vibrating the bag in the direction of its axis. A variety of apparatus for this purpose will readily suggest itself rounding framework at its open lower end, for

to those skilled in the art. Such apparatus is here illustrated by vertical rods attached to the levers 2|. Any known or convenient means for reciprocating these vertical rods 25 may be employed to vibrate the filter bag as described. The simplest method of oscillating the rods 25 is, of course, to grasp themin the hand and move them up and down.

By vibrating the filter bag .in the direction of its axis some of the fume adhering to its inner surface will be displaced. Furthermore, the separate layers of which the bag is formed, will receive some displacement with respect to each other.

The second means for removing fume from the inner surface of the filter bag 12 and to some extent from between the layers of which the filter bag is composed, is provided in an annular fluid ring 26 (Fig. 1) which surrounds the filter bag l2 at a slight interval therefrom. The ring 26 has a series of perforations 21 at its inner face through which air or other fluid under pressure in the ring 26 will be forced from the outer surface of the filter bag l2 through the bag wall. A fluid supply pipe .28 is connected to the ring 26 and a flexible hose 29 is provided for supplying a fluid under pressure to the supply pipe 28. Thus, fluid under pressure coming from the hose connection 29 and passing through the supply pipe 28 to the annularring 26 will be forced through the openings 21 against the outer surface of the porous filter bag through which it will then tend to pass. Fluid passing through the bag toward its inside will pick up fume which has been deposited on the inner surface of the bag or between the fibres thereof and will carry it to the interior of the bag, thus cleaning the bag.

Apparatus is provided for controlling the position of the fluid ring 26 with respect to the filter ag I2. As here illustrated thiS apparatus cOmprises a frame member, generally designated by the numeral 30, attached by rods I30 to the annular ring 26 about its periphery. The frame mempulleys 32 and 33, the cable being operated by a Windlass 34 by means of which it is wound or unwound to elevate or lower the annular ring 26.

A single nozzle l3, to which reference has already been made, is provided for removing fume directly from: the interior surface of the bag. The nozzle l3 extends substantially the entire length ofthe bag (see Fig. 1). A longitudinal slot 35 extending the entire length of the nozzle has its edges 36 in contact with the inner surface of the filter bag. In order to maintain the edges 36 in proper contact with the bag surface, an opposed shoe 31 is disposed in contact with the filter bag l2 at a part thereof diametrically opposite to that at which the nozzle l3 contacts. Both the nozzle and the shoe are carried by a longitudinal axle member 36 from which arms 39 and 40 extend to the nozzle and shoe respectively. Thus, by turning the axle 39, the nozzle and the shoe are turned in contact with the interior surface of the bag. The length of the arms 39 and 40 is preferably such that the nozzle and shoe will stretch the bag into slightly elliptical form,

thereby assisting in maintaining the contact.

Means is provided for adjusting the position of the nozzle l3 and the position of the shoe 31 radially of the bag. As here shown, this means for adjusting the nozzle comprises a plurality of sockets 4| fastened to the axle 38,1nto which the arms 39 flt, combined with a set screw 42 in eacn socket 4| for clamping the end of the corresponding arm 39 therein. Similar means is shown for adjusting the position of the shoe, this means comprising sockets 43, into which the ends of the shoe arms 49 fit, together with the set screws 44 for fixing the extent to which the arms 40 project within the sockets 43. Obviously by loosening the set screws 42 and 44 and by moving the arms 39 and 40 outward and then tightening the set screws, the pressure of nozzle and shoe upon the bag may be increased. By reversing this operation, the pressure of nozzle and shoe may be lessened. It is noted that the arms 39 are of solid construction and do not carry gas from the nozzle l3 to the axle 38.

The nozzle is exhausted through a hollow member 45 adjacent its lower end, in the embodiment shown. This hollow member 45 fits into a sleeve 46 in a centrifugal separator 41 of well-known construction, to which it delivers the fluid which is drawn through the bag by the nozzle l3 (see Fig. 3). Member 45 will slide lengthwise in sleeve 46 slightly when the position of nozzle I3 is adjusted. The 'centifugal separator 41 is disposed within the filter bag l2, and turns with the axle 36 and the shoe l3.

In the centrifugal cyclone separator 41, the fume-laden gas enters tangentially and is whirled about,asindicated, depositing the particles of fume,

apparatus. The carrying fluid, now substantially freed of its burden of fume, passes upward into a chamber 59 above this centrifugal separator, whence it is carried tangentially into a flue 5| which connects with a lower fluid chamber 62 which surrounds the hollow stem 48 adjacent the base of the apparatus. The lower fluid chamber 52 has external flanges 53 and 54 thereon which contact with flanges 55 and 56 respectively of a stationary circular fluid box 51 which surrounds ber 30 is shown as suspended by a cable 3| from the lower part of the fluid chamber- 52. Apertures 58 (see Fig. 3) in the walls of the fluidchamber 52 permit fluid to pass therefrom into the fluid box 51.

It is observed that the fluid chamber 52 revolves with the nozzle l3 and the centrifugal separator 41, whereas the fluid box 51 remains stationary.

A duct 59 connects the fluid box 51 with a centrifugal blower 68 which is operated by a special motor 6|. A fiue 62 leads from the centrifugal blower 60 to the interior of the bag l2, thus recycling the gaseous output of the cyclone separator back into main gas path.

From the foregoing it will be clear that the suction applied to the interior of the filter bag I2 by the nozzle I3 is the result of the exhausting action of the centrifugal blower 60 acting through the duct 59, the fluid box 51, the fluid chamber 52, the flue 5 I, the chamber 50 and the centrifugal separtor 41.

The walls of the rotating fluid chamber 52 terminate in a base member 63 which is keyed as at 64 to a bevel wheel 65. The base member 63 is joumalled in stationary bearing I63. A pinion bevel 66 meshes with the bevel wheel 65 and is driven through a train of gears 61 by a motor 68 which turns the axle 38 together with the nozzle l3 and the shoe 31. It will be understood that the upper end of the axle 38 is journalled in bearing I38 secured to the top wall of the main housing I39 in which the filter bag is suspended.

Thus, in operation the fume-containing gas to be cleaned is passed to the interior of the filter bag l2 through supply pipe 59, and is drawn through the bag by the suction of the main centrifugal blower I8 operated by a motor II. The centrifugal blower 10 is connected with the exterior chamber 12 wherein the filter bag is disposed by a flue I3, and exhausts the filtered fluid into an exhaust flue 14. In passing through the filter bag, the fume is deposited on its interior surface from which it may be removed by vibrating the bag, by passing fluid through it from a surrounding annular fluid ring, or by suctionfrom a rotating nozzle in contact with the inner surface of the bag.

The apparatus which has been described is simple, rugged and easy to operate and maintain. The operations described may be carried on continuously or intermittently in accordance with the requirements of the particular plants to which the invention is applied.

This application is a continuation in part of application Serial No. 625,707, filed July 29, 1932, which matured as Patent No. 1,995,651 on March 26, 1935.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. In a filter for removing solids from fluids, a substantially cylindrical filter bag, a single nozzle extending substantially the entire length of said bag in contact therewith, and an opposed shoe in contact with said bag at apart thereof diametrically opposite to that with which said nozzle contacts, and extending throughout substantially the length of said bag, said shoe tending to maintain perfect contact at all times between said nozzle and said bag.

2. In a filter for removing solids from fluids, a substantially cylindrical filter bag, a single nozzle within said bag extending substantially the entire length of said bag in contact therewith, an opposed shoe in contact with" said bag at a part thereof diametrically opposite to that at which said nozzle contacts, and engageable with a substantial portion of the length of said bags, said shoe tending to maintain perfect contact at all .times'between said nozzle and said bag, and means for supporting the nozzle and for adjusting the position of said nozzle radially of said bag to control the pressure of said nozzle upon said bag, in combination with means for supporting the shoe and for adjusting the position of said shoe radially of said bag to control the pressure of said shoe upon said bag.

3. In afilter for removing solids from fluids, a substantially cylindrical filter bag, a single nozzle extending substantially the entire length of the bag, a contact shoe, means mounting said nozzle and said shoe to engage said bag at substantially diametrically opposite portions, said nozzle and said shoe having their outermost portions disposed at a distance slightly greater than the normal diametral distance across said bag, means for creating a suction in said nozzle, and means for rotating said nozzle and shoe as a unit relative to said bag.

4. In a filter, a filter medium, a rotatable vacuum cleaning assembly comprising a suction head cooperating with said filter medium and a centrifugal separator having its inlet communieating with said suction head, and means for journalling said assembly so that the centrifugal separator rotates bodily about its axis.

5. In a filter for removing fume from gas in which it is suspended, a housing, a filter medium in said housing, a rotatable .vacuum cleaning assembly comprising a suction head cooperating with said filter medium, a centrifugal separator having its inlet communicating with said suction head, a solid-delivering outlet in the lower part of said. separator, a clean gas outlet in the top thereof, a casing surrounding said solid-delivering outlet and having communication with said clean gas outlet, means mounting said assembly principally within said housing for rotation about the axis of said separator, an auxiliary housing surrounding said casing and having communication therewith, and a suction pump connected to said auxiliary housing;

6. In a filter for removing suspended solids from gases, a housing, a filter element defining a filter chamber, means on the inside of said chamber for passing a gaseous cleaning current through said filter element for entraining solids deposited on said filter element, and means principally located within said housing and in the path of the gases to be filtered for separating the entrained solids from said gaseous current.

7. In a filter for removing suspended solids 

